Hi Emanuele, To force a user to make a choice wrt boolean fields, you have two options: a BooleanField or (as you seem to be looking for) a NullBooleanField, which actually represents three states (including 'unselected'). This will mirror what you are trying to achieve with the CharField solution, except that it saves to the database as a boolean field instead of a varchar. Not sure if 'choices' works with NullBooleanField, but it sounds like it should raise an exception for the BooleanField?
-rob
